For chloroform and acetone or for a solution of chloroform and acetone if `P_(s)` (observed (actual)) is compared with `P_(s)` (Theoretical (Raoult)) then which of the following is fare true ?

Options

A. `p_(s("actual")) lt p_(s("raoult"))`
B. `overset("Limit")(X)_("chloroform")rarr0(p_("acetone")^(@)-p_(s "actual"))=0`
C. `overset("Limit")(X_("chloroform"))rarr0(p_("chloroform")^(@)-p_(s ("actual")))=0`
D. `p_("acetone")^(@)gtp_("chloroform")^(@)` near roomtemperature

Answer

To analyze the relationship between the observed vapor pressure (P_s observed) and the theoretical vapor pressure (P_s theoretical) for a solution of chloroform and acetone, we can follow these steps:

### Step 1: Understand Raoult's Law
Raoult's Law states that the vapor pressure of a solvent in a solution is directly proportional to the mole fraction of the solvent in the solution. For a solution of two volatile components, the total vapor pressure can be calculated using the formula:

\[ P_{total} = P^0_A \cdot X_A + P^0_B \cdot X_B \]

where:
- \( P^0_A \) and \( P^0_B \) are the vapor pressures of pure components A (chloroform) and B (acetone), respectively.
- \( X_A \) and \( X_B \) are the mole fractions of components A and B in the solution.

### Step 2: Identify the Nature of the Deviation
In the case of chloroform and acetone, it is known that this combination exhibits a negative deviation from Raoult's Law. This means that the observed vapor pressure of the solution is lower than what would be predicted by Raoult's Law.

### Step 3: Compare Observed and Theoretical Vapor Pressures
Since the solution shows a negative deviation, we can conclude that:

\[ P_s \, (observed) < P_s \, (theoretical) \]

This indicates that the interactions between chloroform and acetone molecules are stronger than the interactions between the molecules of the pure components, leading to a lower vapor pressure.

### Conclusion
For the solution of chloroform and acetone, it is true that the observed vapor pressure (P_s observed) is less than the theoretical vapor pressure (P_s theoretical) according to Raoult's Law, indicating a negative deviation.